Outcome of Surgery in different Parotid Neoplasms

Objective: To determine outcome of surgery in different parotid neoplasms. Study design: Cross sectional study from August 2010 to July 2014. Settings: Department of Otolaryngology and Head-Neck Surgery, Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh. Method: 60 postoperative patients of different parotid neoplasms were included in this study. 33 were males and 27 were females between 21 years to 80 years who were treated between August 2010 to July 2014. The study based on history, clinical examinations, radiological, laboratory, cytology reports and histopathological examination. Results: Majority of the patients were within 41 to 70 years of age. Frequency of benign tumour were more in 4th and 5th decade 42(87.5%) and malignant tumour in 5th and 6th decade 8(66.7%). Common presenting features were pain 8(66.7%), skin involvement 3(25.0%), facial nerve palsy 3(25.0%), metastatic neck nodes 3(25.0%) in malignant cases. In benign cases 45(93.7%) were pleomorphic adenoma, 3(6.25%) Warthin’s tumour. In malignant cases mucoepidermoid carcinoma were 7(58.3%), adenoid cystic carcinoma 3(25.0%). In benign parotid tumour, superficial parotidectomy were done in 45(93.75%) and total conservative parotidectomy 3(6.25%). In malignant tumour total conservative parotidectomy were done 5(41.7%), total radical parotidectomy done 4(33.3%), extended radical parotidectomy 3(25%). Histopathological study showed 45(93.75%) were in pleomorphic adenoma, 7(58.3%) mucoepidemoid carcinoma. Key word: Parotid neoplasm, surgical outcome. 1. Assistant Professor, Department of Otolaryngology and Head-Neck Surgery, BSMMU 2. Professor and Chief, Head-Neck Surgery Division, BSMMU 3. Associate Professor, Dept. of Otolaryngology and Head-Neck Surgery, BSMMU 4. Assistant Professor, Dept. of Otolaryngology and Head-Neck Surgery, BSMMU 5. Assistant Professor, Dept. of Otolaryngology and Head-Neck Surgery, BSMMU Address of Correspondence: Dr. Kazi Shameemus Salam, Assistant Professor, Department of Otolaryngology and Head-Neck Surgery, BSMMU, Mobile: 01711846700. Introduction The parotid gland is the largest gland among all the salivary glands. It is divided into superficial and deep lobes by the traversing facial nerve and its branches. The superficial lobe is the site mostly involved 90% by neoplasms. While the deep lobe tumours accounts for approximately 10% of the parotid tumours.1 Salivary gland tumours represent about 3% of all the neoplasms of head and neck.2 approximately 80% tumours are located in the parotid gland. 80% are benign in nature. 80% are pleomorphic adenomas followed by warthin’s tumours are 4-14%.3,4 If there is clinical evidence of bilateral parotid 2 Bangladesh J Otorhinolaryngol Vol. 20, No. 2, October 2014


Introduction
The parotid gland is the largest gland among all the salivary glands.It is divided into superficial and deep lobes by the traversing facial nerve and its branches.The superficial lobe is the site mostly involved 90% by neoplasms.While the deep lobe tumours accounts for approximately 10% of the parotid tumours. 1 Salivary gland tumours represent about 3% of all the neoplasms of head and neck. 2 approximately 80% tumours are located in the parotid gland.80% are benign in nature.80% are pleomorphic adenomas followed by warthin's tumours are 4-14%. 3,4f there is clinical evidence of bilateral parotid swelling warthin's tumour should be suspected, being the most frequent synchronous or metachronous bilateral histological type. 5,6ucoepidermoid carcinoma is the commonest malignant tumour account for 4-9% of the salivary tumours. 7 the 19 th century, enucleation was performed for parotid gland tumors which was had 25% recurrence rate.In the 20 th century, the concept for more extensive surgery to reduce the high rate of recurrence came and superficial parotidectomy became popular as the minimum procedure.Today, the widely accepted procedure for benign parotid gland tumours is superficial parotidectomy while for malignant tumors, the option ranges from total to extended parotidectomy followed by post operative radiation for tumors with residual disease or positive lymph nodes.

Methods
This surgical audit was carried out at the Department of Otolaryngology and Head-Neck Surgery, Bangabandhu Sheikh Mujib Medical University, Dhaka from August 2010 to July 2014.All adult patients of both sexes who presented with parotid gland tumour and underwent parotidectomy were included.Patients with diseases such as parotitis, parotid abscess were excluded.Initial diagnosis was done by history, clinical examinations, laboratory, FNAC and radiological evaluations.Surgery, histopathological examination, complications and outcome was noted.

Discussion
This series focused on parotid gland neoplasm which is the commonest site among all the salivary glands.[11][12] In this study, among 60 patients 26 were males and 22 were females in benign and 7 were males and 5 were females in malignant diseases.So these were a slight male predominance.Several published studies have reported more frequent involvement of females than males. 13Dorairajan from India reported male predominance. 14 this study, age ranged from 21 to 80 years.Majority of the patients 42(70.0%)were in 4 th and 5 th decade in benign and 5 th and 6th decades in malignant disease.Several studies from the west have reported these disorders to be more common in relatively advanced age group. 15 this study one tumour was originated from the deep lobe of the parotid presented with a swelling of lateral pharyngeal wall.Sign of malignancy were pain 8(66.7%),fixity to the skin 3(25.0%),facial nerve paralysis 3(25.0%),lymph node metastasis 3(25.0%) and trismus 2(16.7%).According to Thackray et al pain is infrequent in adenoid cystic carcinoma but in squamous cell carcinoma pain is observed in ¾ of the patients.There may be intractable pain due to involvement of nerve and base of the skull and there may be associated paralysis of the cranial nerve. 16,17acial nerve paralysis occurs only 3(25.0%) in malignant cases.Benign tumours had no facial nerve involvement.Malignancy may involve the trunk or any branch of facial nerve.
According to Eneroth's work involvement of the facial nerve in malignant parotid tumour is 40%. 18 this study pleomorphic adenoma was the commonest 45(93.75%)benign tumour affecting the parotid gland followed by Warthins tumour 3(6.25%).Most of the literature had reported pleomorphic adenoma was the commonest pathology affecting the parotid gland. 19The share of malignancy was about 12, Kara et al. had reported 24% malignancies in parotid gland disorders. 12akahama et al. have reported even higher frequency of malignancies upto 40%. 15In this series the commonest malignant tumour was mucoepidermoid carcinoma followed by adenoid cystic carcinoma.This findings was consistent with most of the literature. 20garding investigations of my series FNAC was found to be very useful in parotid gland pathology.It was done in all 60 cases (100%) of which 55(91.7%) were positive and related with the study of Lindberg and Ackerman 21 25,26 Numbness of the ear occurs in 5(8.3%) cases due to cutting of great aricular nerve.Recovery of sensation may be slow.
In the present series follow up could be made for 4 years none of the pleomorphic adenoma showed any recurrence.The warthin's tumour had no recurrence and facial nerve palsy.
There were 2 cases of facial nerve palsy and no recurrence in mucoepidermoid carcinoma, in adenocystic carcinoma 3 were facial nerve palsy and 1 recurrence.In adenocarcinoma 1 facial nerve palsy and 1 recurrence, carcinoma ex-pleomorphic adenoma 1 facial nerve palsy and no recurrence.

Conclusion
Parotid gland is the principle site of salivary gland tumours.Males are mostly affected.Majority of patients present with painless lump and pleomorphic adenoma is the commonest benign tumour, while mucoepidermoid carcinoma is the most common malignant tumour.Superficial parotidectomy were the most commonly offered surgical procedure and post operative risk of facial nerve palsy and recurrence were decreased.

Table - II
Incidence of different types of parotid tumour (N=50)

Table - V
Histological grading for malignant parotid gland tumour